This sounds like a comment based on your personal opinion. That's ok, we all have our preferences when it comes to fonts.

A bigger issue is probably the headings not fitting in the page column.

https://screenshots.firefox.com/fsetQcI74tLZbwkd/betterwebty...

[Edit: I probably should switch off webfont blocking when checking an article on fonts]

How so?

Letters are too close. It is hard to read.

IMHO of course!

I'd agree with this, and the article itself makes the point that increased spacing for all caps headings can be beneficial. To me those headings lack horizontal rhythm, they're just black rectangular slabs.